Thermochromic acrylic synthetic fiber, its processed article, and process for producing thermochromic acrylic synthetic fiber

Abstract

A thermochromic acrylic synthetic fiber comprising an acrylonitrile polymer in which a thermochromic pigment composition with an average particle diameter of from 0.5 μm to 30 μm is dispersedly contained in an amount of from 0.5% by weight to 40% by weight based on the weight of the polymer, and being made into fibers; the pigment composition containing (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound and (c) a reaction medium that determines the temperature at which the color-developing reaction of the both compounds takes place. Also disclosed are a processed article of the above thermochromic acrylic synthetic fiber, and a process for producing the thermochromic acrylic synthetic fiber.

What is claimed is:  
     
       1. A thermochromic acrylic comprising: 
       an acrylonitrile polymer having thermochrornic microcapsules dispersed therein, said thermochromic microcapsules having a non-round particle cross-section and an average particle diameter of from 0.5 μm to 30 μm;  
       said thermochromic microcapsules containing a reversible thermochromic pigment composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound and (c) a reaction medium affecting the temperature at which the color-developing reaction of the both compounds takes place;  
       said thermochromic microcapsules having a hollow at a portion of their particle outer surface and having a weight ratio of reversible thermochromic pigment composition/wall film of from 7/1 to 1/1;  
       said thermochromic microcapsules being contained in an amount of from 0.5% to 40% by weight based on the weight of the acrylonitrile polymer, wherein said thermochromic acrylic is formed into fibers.  
     
     
       2. The thermochromic acrylic according to  claim 1 , wherein said thermochromic pigment composition is selected from any one of a heat-color-extinguishing type capable of color-extinguishing upon heating from a color-developed state and developing a color upon cooling from a color-extinguished state, a color-memorizing type capable of memorizing a color-developed state and a color-extinguished state alternately in a specific temperature region, and a heat-color-developing type capable of developing a color upon heating from a color-extinguished state and restoring to the color-extinguished state upon temperature drop from a color-developed state. 
     
     
       3. A processed article comprising a plurality of filaments of long fibers or short fibers of the thermochromic acrylic according to  claim 2 , having a single-fiber external diameter of from 1 μm to 100 μm; the filaments are in a bundled, close-contact or massed state. 
     
     
       4. The processed article according to  claim 3 , which is any of tow, a sliver, a cottony aggregate yarn, cloth, flocked fabric, raised fabric and papermaked fabric. 
     
     
       5. The processed article according to  claim 4  which is a cloth, wherein said cloth is any of woven fabric, knitted fabric, nonwoven fabric and pile fabric. 
     
     
       6. The processed article according to any one of  claims 3  to  5 , which is a wig, a hairpiece or a dole's or animal toy's hair of the head, hair of bodies or outer garments comprising filament yarn, spun yarn, wool-yarn-like crimped yarn or pile fabric. 
     
     
       7. The processed article according to  claim 5 , which is a dole's or animal toy's cloth, outer garments or accessories comprising any of woven fabric, knitted fabric, nonwoven fabric and pile fabric. 
     
     
       8. The processed article according to any one of  claims 3  to  5 , which further comprises a non-thermochromic fiber blended in an amount of from 0.01 part by weight to 20 parts by weight based on 1 part by weight of the thermochromic acrylic synthetic fiber.